The Midrash (Midrash Rabbah, Song of Songs 1:3,1) relates that when the Jewish people stood at Mount Sinai to receive the Torah, God asked for a guarantee that they would keep it.
They replied, “Our ancestors will be our guarantors.” When this was not accepted, they offered, “Our prophets will be our guarantors.” Finally they said, “Our children will be our guarantors.” God replied, “Indeed these are good guarantors. For their sake I will give it to you.”
